Apple's Retina display--now trademarked, mind you--expanded from the iPad to the MacBook last year, and a visual revolution has followed. App makers and websites had to adjust to the new pixel-packed screen (which is so good that a user with 20/20 vision can't see individual pixels from a normal viewing distance) or else products would look like an actor without makeup on an HDTV. But the best sign of Apple's influence comes from the feverish attempts by rivals to hype their own tablet displays. Google's Nexus 10 paraded 300 pixels per inch, to iPad's 264; Microsoft contorted itself into arguing that the Surface RT made up for its 148 pixels with a magical "subpixel rendering"; and Amazon CEO Jeff Bezos boasted that his new Kindle Fire HD's 254 pixels came with an "Advanced True Wide polarizing filter." Alas, competitors can't make invisible pixels even more invisible.